The following code shows how to display the default raster image export dialog provided by NOV:

NChartRasterImageExporter imageExporter = new NChartRasterImageExporter(chartView.Content);
imageExporter.ShowDialog(DisplayWindow, true);

The following code shows a save image file dialog that allows the user to create an image from a chart:

NChartRasterImageExporter imageExporter = new NChartRasterImageExporter(chartView.Content);
imageExporter.SaveAsImage(NImageFormat.Png); // Save to image with PNG file format selected by default

To export the chart to a raster image and save it directly to a file, without showing a save file dialog, you can use the SaveToFileAsync method. Note that the saving to file is an asynchronous (async) operation, so if you are interested in its completion, you should call the Then method of the promise it returns and handle the completion of the export in the passed delegate. Following is a code example that shows how to achieve this:

NChartRasterImageExporter imageExporter = new NChartRasterImageExporter(chartView.Content);
imageExporter.SaveToFileAsync("C:\\ExportedImage.png").Then(
    delegate (NUndefined ud)
    {
        // Export to PNG completed
    }
);

To export the chart to an image stream, you can use the SaveToStream method. Unlike the SaveToFileAsync method, the SaveToStream method runs synchronously and blocks code execution until it completes. Exporting charts to stream is useful when you wish to generate images in memory instead of saving them to the disc. The following code snippet shows how to export the active page of a chart to a stream:

NChartRasterImageExporter imageExporter = new NChartRasterImageExporter(chartView.Content);
imageExporter.SaveToStream(stream, NImageFormat.Png);

To generate an image on the fly without saving it, use the CreateImage method:

NChartRasterImageExporter imageExporter = new NChartRasterImageExporter(chartView.Content);
NImage image = imageExporter.CreateImage();

To copy the image to the clipboard, use the CopyToClipboard method:

NChartRasterImageExporter imageExporter = new NChartRasterImageExporter(chartView.Content);
imageExporter.CopyToClipboard();